private static HitRecord GetHitPoint(Ray ray, HitRecord hit)
{
var r = ray.At(hit.T);
hit.Point = new Point(r.X, r.Y, r.Z);
return(hit);
}
public override bool Hit(Ray r, double tMin, double tMax, out Object3D rec)
{
var oc = r.Origin - Center;
var a = r.Direction.LengthSquared;
var halfB = Vector3.DotProduct(oc, r.Direction);
var c = oc.LengthSquared - Radius * Radius;
var discriminant = halfB * halfB - a * c;
if (discriminant > 0)
{
var root = Math.Sqrt(discriminant);
var temp = (-halfB - root) / a;
if (temp < tMax && temp > tMin)
{
rec = new Sphere(Center, Radius, Material);
rec.T = temp;
rec.P = r.At(rec.T);
var outwardNormal = (rec.P - Center) / Radius;
rec.SetFaceNormal(r, outwardNormal);
return(true);
}
temp = (-halfB + root) / a;
if (temp < tMax && temp > tMin)
{
rec = new Sphere(Center, Radius, Material);
rec.T = temp;
rec.P = r.At(rec.T);
var outwardNormal = (rec.P - Center) / Radius;
rec.SetFaceNormal(r, outwardNormal);
return(true);
}
}
rec = null;
return(false);
}